Pneumatic tool.



No. 665,281. Patented Jan. 1, mm. J. s. STEVENSON.

PNEUMATIC TOOL.

} (Application filed Oct. 8, 1900.) (No Model.) 2 Sheets-Sheet 2.

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NITED STATES P TENT FFICE.

JOHN S. STEVENSON, OF DETROIT, MICHIGAN, ASSIGNOR TO THE AMERICAN CARAND FOUNDRY COMPANY, OF SAME PLACE.

PNEUMATIC TOOL.

SPECIFICATION formingpart of Letters Patent No. 665,281, dated January1, 1901.

Application filed October 8,1900. SerialNo. 32,445. (No model.)

To all whom it may concern:

Be it known that 1, JOHN S. STEVENSON, a citizen of the United States,residing at Detroit, in the county of Wayne and State of Michigan, haveinvented certain new and useful Improvements in Pneumatic Tools, ofwhich the following is a specification, reference being had therein tothe accompanying drawings.

The invention relates to pneumatic tools, and more particularly to thatclass intended for use in tightening nuts on bolts and for similarpurposes.

Heretofore pneumatic tools have been der5 signed for the above purposes;but it has been found in the practical use of such tools that thevibration caused by the rapid movement of the parts is exceedinglytiring to the workman.

It is the object of my invention to obtain a construction which is freefrom this objection and which at the same time is-simple, efficient,andeasy to manufacture.

The in ventionconsists in the peculiar construction of a cylinder, apiston therein, and a rotatable tool-holder having a connection withsaid piston, whereby the reciprocating movement of the latter willimpart a rotatory movement continuousin one direction to thetool-holder.

The invention further consists in the peculiar construction,arrangement, and combination of parts, as hereinafter described andclaimed.

In the drawings, Figure 1 is a perspective view of the tool. Fig. 2 isalongitudinal section therethrough. Fig. 3 is a cross-section on line 00m, Fig. 2, upon alarger scale. Fig.

4 is a plan view.

A is a cylinder, and B is a piston therein.

At one end of the cylinder is arranged, at

right angles to the axis thereof, a cylindrical casing 0, preferablyformed integral with a detachable head D of the cylinder. IVithin thecasing O is journaled a rotary spindle or toolholder E. This spindle hasa shank F extending out from one end of the casing O and carrying at itsend any suitable tool, such as the wrench G.

H H are sleeves loosely fitting upon the spindle E and within the boreof the casing C. These sleeves have centrally formed thereon acircumferential series of teetha, forming a pinion, the externaldiameter of which will fit within the bore of the casing O. The adjacentends of the sleeves H and H have formed therein annular recesses b,

in which is arranged a coil-spring I, sleeved upon the spindle E.

J and J are collars arranged at the opposite outer ends of the sleeves Hand H and secured to the spindle E. The adjacent faces of the collar Jand sleeve H are formed with engaging ratchet-teeth,and the adjacentfaces of the collar J and sleeve H are provided with similar teethturned in opposite directions.

L and L are caps screwed or otherwise secured to the casing O andbearing upon the outer faces of the collars J and J, so as to form apractically air-tight joint. Upon opposite sides of the casing O andrespectively in the central planes of the sleeves H and H are arrangedpiston-rods M M, which are secured to the piston B and pass outwardthrough suitable apertures in the head D. These piston-rods have formedupon their inner faces rack-bars 1), adapted to engage with the teeth aof the sleeves H and H, respectively. Surrounding the rods M and M arecasings N N, extending outward a sufficient distance to permit the fullstroke of the piston B and which form air-tight housings for said rods Mand M.

O O are valve-casings arranged atopposite ends of the cylinder A andpreferably formed integral, respectively, with the cylinder-casing andthe head D. Within these casings are arranged valves P P for controllingair admission and exhaust to the opposite ends of the cylinder. As shownin Fig. 2, these valves are of the piston-valve type and fit within thebores of their respective casings, each being provided with anoperating-shank c, passing outward through a cap (1 of the casing, bymeans of which the position of the valve may be shifted. As shown, thevalve P comprises two separated heads 6 and f, forming an annular spaceg between, which in the position shown in Fig. 2 communicates with aport h, leading from the valve-casing into the cylinder. In thisposition of the valve the channel g also communicates with a port i,connecting with the passage j, form ed in the wall of the cylinder andleading to the air-supply conduit Q.

The construction of the valve P is similar to that of the valve P, butin the position shown in Fig. 2 the channel g is cutoff from connectionwith the port 71 by the head f. In this position the channel gcommunicates with the port 7t and also an exhaust-port l, leading outfrom the casing O. m and hi are springs bearing against the valves P andP, respectively, and tending to hold said valve in the position of thevalve P, Fig. 2.

From the description of parts as above given it will be readilyunderstood that the air is admitted through the conduit Q and passage j,where it will be normally cut off from both ends of the cylinder by thevalves P P, which, as stated, are held in such positions by the springsm and m. As, however, the valves P and P are balanced, a slight pressureon the stem 0 of either one will be sufficient to shift the valve intothe position of the valve P, Fig. 2. This will admit compressed air orother motive agent from the channel j through the ports 2: into thecylinder, where it will cause the piston B to travel toward the oppositeend. In the movement of the piston the racks of the two rods M and Mengaging with the pinions of their respective sleeves H and H will causesaid pinions to rotate in opposite directions. At the same time thespring I will press the sleeves H and H against the collars J and J,respectively. As, however, the ratchet-teeth areturnedoppositely on thetwo sleeves, the collar J only will be driven, while the sleeve H willslip in its engagement with the collar J. Thus a rotary movement will beimparted to the spindle E and through the shank F to the wrench or toolG. When the piston has reached the end of the cylinder, if additionalrotation is required the valve P may be re leased and the valve Poperated, which will admit the motive agent into the opposite end of thecylinder and allow the compressed air previously admitted to exhaust. Inthe reverse movement of the piston the sleeve H will engage with thecollar J, while the sleeve II will slip in its engagement with thecollar J, thereby continuing to rotate the tool in the same direction.

The shape and the sizeof the cylinder and other parts of the casing aresuch that the operator may conveniently hold the tool in engagement withthe work with one hand at each end of the cylinder, and the valves P andP are so located that they may be controlled by the thumbs. In order toprovide a convenient handheld, a handle R is preferably arranged at oneend of the cylinder, and the housing N N will serve a similar purpose atthe opposite end of the cylinder.

By the term pneumatic tool as used in tion to the use of compressed aironly, as it is obvious that any fluid under pressure might be employedequally well for the motive agent.

What I claim as my invention isl. In a pneumatic tool, the combinationwith the cylinder and the piston therein, of a rotatable tool-carryingmember, rack-bars directly connected to the piston and extending fromthe latter through the cylinder-casing, pinions sleeved on the rotatablemember with which the rack-bars engage, and mechanism for alternatelylocking said pinions to the rotatable member upon the reciprocatorymovement of the piston.

2. In a pneumatic tool, the combination with the cylinder and the pistontherein, of a rotatable tool-carrying member journaled in bearings atone end of the cylinder, rackbars directly connected to the piston andextending from the latter through the cylindercasing upon opposite sidesof the rotatable member, pinions sleeved upon the latter with which therack-bars engage, and means for alternately locking said pinions to therotatable member upon the reciprocating movement of the piston.

3. In apnenmatic tool, the combination with the cylinder and its piston,of a rotatable tool-carrying member projecting from one side of thecylinder, a drive mechanism for said member operated by the piston, ahousing for the drive mechanism projecting from one end of the cylinder,and a handle at the opposite cylinder end, substantially as described.

:L. A pneumatic tool comprising a cylinder, at reciprocatory pistontherein, a rotatable spindle journaled in bearings at one end of saidcylinder and extending perpendicular to the axis thereof, piston-rodsextending upon opposite sides of said spindle and having a rotatoryratchet-driving engagement therewith adapted to alternately rotate thespindle and in the same direction, and an air-tight housing inclosingsaid piston-rods and spindle.

5. A pneumatic tool, comprising a cylinder, a reciprocatory pistontherein, a rotatable spindle extending perpendicular to the axis of saidcylinder, a drive connection between said piston and rotatable spindlefor imparting rotary movement in the same direction to the latter by thereciprocatory movement of the former, balanced valves at each end of thecylinder for controlling admission and exhaust upon opposite sides ofthe piston, means for yieldingly holding said valves normally in theirexhaust positions, and thumb-pins for operating said valves.

In testimony whereof I affix my signature in presence of two witnesses.

JOHN S. STEVENSON.

Witnesses:

M. B. ODOGHERTY,

the claims I do not intend to limit my inven- H. 0. SMITH.

ICC

